Grand Junction, CO Vegetable Planting Calendar

What to plant now in Grand Junction

In October:

• Plant garlic cloves (Oct 1–14)

The list above is for the month this page was built; the box is refreshed in your browser for today's date.

Spring planting dates

“Plant out” means transplanting for crops started indoors and sowing or planting directly in the garden for the others. Each column applies CSU Extension's timing rule to a different last-frost anchor: aggressive = typical date (Apr 28, 50% risk), balanced = May 3 (30%), safe = May 14 (10%). For hardy crops the cell shows the CSU “as early as” window.

A soil thermometer helps here. CSU recommends checking soil temperature at 4 inches (6 inches for beans) before sowing. NOAA doesn't publish soil-temperature normals, so instead of a date, each crop shows CSU's minimum soil temperature.

Fall planting dates

Latest dates for a fall harvest, using the University of Nebraska–Lincoln Extension count-back formula: days to harvest (CSU) + 14-day fall factor + 14-day frost-tender factor for frost-sensitive crops, counted back from the first-frost date. For transplanted crops (CSU days are from transplant) the result is the latest transplant date; seeds go in CSU's transplant-age weeks earlier. We add no harvest period, so these dates give you a first harvest by the first frost, not a long harvest.

Month-by-month: what to plant in Grand Junction

What to plant in Grand Junction in February

• Start broccoli seeds indoors (Feb 15 – Mar 1)
• Start cabbage seeds indoors (Feb 15 – Mar 1)

What to plant in Grand Junction in March

• Start cauliflower seeds indoors (Mar 1–15)
• Start eggplant seeds indoors (Mar 15 – Apr 5)
• Start pepper seeds indoors (Mar 22 – Apr 5)
• Onions (dry, from sets): plant sets outdoors (Mar 31 – Apr 30)
• Peas: direct sow outdoors (Mar 31 – Apr 30)
• Lettuce (leaf): direct sow outdoors (Mar 31 – Apr 30)
• Broccoli: transplant outdoors (Mar 31 – Apr 30)
• Cabbage: transplant outdoors (Mar 31 – Apr 30)
• Kohlrabi: direct sow outdoors (Mar 31 – Apr 30)
• Green onions: direct sow outdoors (Mar 31 – Apr 30)
• Radishes: direct sow outdoors (Mar 31 – Apr 30)
• Spinach: direct sow outdoors (Mar 31 – Apr 30)
• Turnips: direct sow outdoors (Mar 31 – Apr 30)
• Start broccoli seeds indoors (Feb 15 – Mar 1)
• Start cabbage seeds indoors (Feb 15 – Mar 1)

What to plant in Grand Junction in April

• Start tomato seeds indoors (Apr 13–27)
• Potatoes: plant (seed pieces) outdoors (Apr 14 – May 14)
• Carrots: direct sow outdoors (Apr 14 – May 14)
• Cauliflower: transplant outdoors (Apr 14 – May 14)
• Beets: direct sow outdoors (Apr 14 – May 14)
• Swiss chard: direct sow outdoors (Apr 14 – May 14)
• Parsnips: direct sow outdoors (Apr 14 – May 14)
• Beans (snap): direct sow outdoors (Apr 28 – May 14)
• Summer squash: direct sow outdoors (Apr 28 – May 14)
• Sweet corn: direct sow outdoors (Apr 28 – May 14)
• Cucumbers: direct sow outdoors (Apr 28 – May 14)
• Start eggplant seeds indoors (Mar 15 – Apr 5)
• Start pepper seeds indoors (Mar 22 – Apr 5)
• Onions (dry, from sets): plant sets outdoors (Mar 31 – Apr 30)
• Peas: direct sow outdoors (Mar 31 – Apr 30)
• Lettuce (leaf): direct sow outdoors (Mar 31 – Apr 30)
• Broccoli: transplant outdoors (Mar 31 – Apr 30)
• Cabbage: transplant outdoors (Mar 31 – Apr 30)
• Kohlrabi: direct sow outdoors (Mar 31 – Apr 30)
• Green onions: direct sow outdoors (Mar 31 – Apr 30)
• Radishes: direct sow outdoors (Mar 31 – Apr 30)
• Spinach: direct sow outdoors (Mar 31 – Apr 30)
• Turnips: direct sow outdoors (Mar 31 – Apr 30)

What to plant in Grand Junction in May

• Peppers: transplant outdoors (May 12–28)
• Eggplant: transplant outdoors (May 12–28)
• Cantaloupe: direct sow outdoors (May 12–28)
• Watermelon: direct sow outdoors (May 12–28)
• Winter squash: direct sow outdoors (May 12–28)
• Start cabbage seeds indoors for a fall crop (May 21 – Jun 4)
• Potatoes: plant (seed pieces) outdoors (Apr 14 – May 14)
• Carrots: direct sow outdoors (Apr 14 – May 14)
• Cauliflower: transplant outdoors (Apr 14 – May 14)
• Beets: direct sow outdoors (Apr 14 – May 14)
• Swiss chard: direct sow outdoors (Apr 14 – May 14)
• Parsnips: direct sow outdoors (Apr 14 – May 14)
• Beans (snap): direct sow outdoors (Apr 28 – May 14)
• Summer squash: direct sow outdoors (Apr 28 – May 14)
• Sweet corn: direct sow outdoors (Apr 28 – May 14)
• Cucumbers: direct sow outdoors (Apr 28 – May 14)

What to plant in Grand Junction in June

• Tomatoes: transplant outdoors (Jun 1)
• Start broccoli seeds indoors for a fall crop (Jun 10–24)
• Start cabbage seeds indoors for a fall crop (May 21 – Jun 4)

What to plant in Grand Junction in July

• Last day to set out cabbage transplants for a fall harvest (by Jul 9)
• Last day to sow beans (snap) for a fall harvest (by Jul 20)
• Last day to sow carrots for a fall harvest (by Jul 24)
• Last day to sow cucumbers for a fall harvest (by Jul 25)
• Last day to sow peas for a fall harvest (by Jul 29)
• Last day to set out broccoli transplants for a fall harvest (by Jul 29)
• Last day to sow summer squash for a fall harvest (by Jul 30)

What to plant in Grand Junction in August

• Last day to sow lettuce (leaf) for a fall harvest (by Aug 3)
• Last day to sow green onions for a fall harvest (by Aug 3)
• Last day to sow beets for a fall harvest (by Aug 3)
• Last day to sow swiss chard for a fall harvest (by Aug 3)
• Last day to sow kohlrabi for a fall harvest (by Aug 13)
• Last day to sow turnips for a fall harvest (by Aug 13)
• Last day to sow spinach for a fall harvest (by Aug 23)

What to plant in Grand Junction in September

• Last day to sow radishes for a fall harvest (by Sep 2)

What to plant in Grand Junction in October

• Plant garlic cloves (Oct 1–14)

Crop-by-crop notes

When to plant tomatoes in Grand Junction

Very tender crop. Set tomatoes out about Jun 1, whichever risk level you go by. That date comes from CSU Extension's night rule (nights above 52°F): the average nightly low at Grand Junction Walker Field first rises above 52°F on Jun 1. CSU's other rule, at least 2 weeks after the average last frost, would allow about May 12 in Grand Junction. Sow seeds indoors Apr 13–27, 5–7 weeks before transplanting on Jun 1. Below 55°F at night, fruit set suffers (CSU). At Grand Junction Walker Field, the normal low reaches 55°F on Jun 10. CSU's typical time from transplant to harvest for tomato plants is 65 days. Set out on Jun 1, they would start producing around Aug 5, 72 days before the typical first frost (Oct 16).

When to plant peppers in Grand Junction

Very tender crop. Following CSU Extension's rule (2+ weeks after the average last frost), set peppers out around May 12 with the typical date, May 17 for a balanced choice, or May 28 with the safer 10% date. Sow seeds indoors Mar 22 – Apr 5, 6–8 weeks before transplanting on May 17. Fruit set suffers when nights drop below 55°F (CSU). The normal low at Grand Junction Walker Field reaches 55°F on Jun 10. CSU's typical time from transplant to harvest for pepper plants is 70 days. Set out on May 17, they would start producing around Jul 26, 82 days before the typical first frost (Oct 16).

When to plant potatoes in Grand Junction

Semi-hardy crop. Per CSU, potatoes can go in as early as 0–2 weeks before the average last frost: roughly Apr 14–28 in Grand Junction (typical date) or Apr 30 – May 14 (safer date). The soil should be at least 45°F.

When to plant onions (dry, from sets) in Grand Junction

Hardy crop. CSU says onions (dry, from sets) can go in as early as 2–4 weeks before the average last frost: roughly Mar 31 – Apr 14 in Grand Junction using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 35°F.

When to plant peas in Grand Junction

Hardy crop. CSU says peas can go in as early as 2–4 weeks before the average last frost: roughly Mar 31 – Apr 14 in Grand Junction using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 40°F. For fall, sow by Jul 29 (Jul 16 to be safe), which is 79 days before the first-frost date.

When to plant lettuce (leaf) in Grand Junction

Hardy crop. Per CSU, lettuce (leaf) can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 35°F. For Grand Junction, that works out to roughly Mar 31 – Apr 14 (typical date) or Apr 16–30 (safer date). For a fall crop, sow by Aug 3, or by Jul 21 to be safe. That's 74 days back from the first-frost date.

When to plant carrots in Grand Junction

Semi-hardy crop. CSU says carrots can be planted as early as 0–2 weeks before the average last frost, in soil of at least 40°F. In Grand Junction, that's roughly Apr 14–28 going by the typical date, or Apr 30 – May 14 going by the safer date. For a fall crop, sow by Jul 24, or by Jul 11 to be safe. That's 84 days back from the first-frost date.

When to plant beans (snap) in Grand Junction

Tender crop. Sow beans (snap) around the average last frost, per CSU: about Apr 28 in Grand Junction. Waiting until May 14 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 55°F. For a fall crop, sow by Jul 20, or by Jul 7 to be safe. That's 88 days back from the first-frost date.

When to plant summer squash in Grand Junction

Tender crop. Sow summer squash around the average last frost, per CSU: about Apr 28 in Grand Junction. Waiting until May 14 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 60°F. For a fall crop, sow by Jul 30, or by Jul 17 to be safe. That's 78 days back from the first-frost date.

When to plant broccoli in Grand Junction

Hardy crop. CSU says broccoli can go in as early as 2–4 weeks before the average last frost: roughly Mar 31 – Apr 14 in Grand Junction using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 40°F. CSU's typical time from transplant to harvest for broccoli plants is 65 days. Set out on Apr 5, they would start producing around Jun 9, 129 days before the typical first frost (Oct 16). For a fall crop, set broccoli transplants out by Jul 29. That's UNL Extension's count-back from the typical first frost (Oct 16), using CSU's 65 days from transplant to harvest. If you grow your own transplants, start seeds Jun 10–24 (CSU: 5–7 weeks to transplant size).

When to plant cabbage in Grand Junction

Hardy crop. CSU says cabbage can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 40°F. In Grand Junction, that's roughly Mar 31 – Apr 14 going by the typical date, or Apr 16–30 going by the safer date. CSU's typical time from transplant to harvest for cabbage plants is 85 days. Set out on Apr 5, they would start producing around Jun 29, 109 days before the typical first frost (Oct 16). For a fall crop, set cabbage transplants out by Jul 9. That's UNL Extension's count-back from the typical first frost (Oct 16), using CSU's 85 days from transplant to harvest. If you grow your own transplants, start seeds May 21 – Jun 4 (CSU: 5–7 weeks to transplant size).

When to plant cauliflower in Grand Junction

Semi-hardy crop. CSU allows planting cauliflower as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Grand Junction, that's roughly Apr 14–28 by the typical date or Apr 30 – May 14 by the safer date.

When to plant kohlrabi in Grand Junction

Hardy crop. CSU says kohlrabi can go in as early as 2–4 weeks before the average last frost: roughly Mar 31 – Apr 14 in Grand Junction using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 40°F. For fall, count back 64 days from the first-frost date. That means sowing by Aug 13, or by Jul 31 to be safe.

When to plant green onions in Grand Junction

Hardy crop. Per CSU, green onions can be planted as early as 2–4 weeks before the average last frost, as long as the soil is workable and at least 35°F. For Grand Junction, that works out to roughly Mar 31 – Apr 14 (typical date) or Apr 16–30 (safer date). For fall, sow by Aug 3 (Jul 21 to be safe), which is 74 days before the first-frost date.

When to plant radishes in Grand Junction

Hardy crop. CSU says radishes can go in as early as 2–4 weeks before the average last frost: roughly Mar 31 – Apr 14 in Grand Junction using the typical date, or Apr 16–30 using the safer one. Wait until the soil can be worked and is at least 40°F. For fall, count back 44 days from the first-frost date. That means sowing by Sep 2, or by Aug 20 to be safe.

When to plant spinach in Grand Junction

Hardy crop. CSU says spinach can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 40°F. In Grand Junction, that's roughly Mar 31 – Apr 14 going by the typical date, or Apr 16–30 going by the safer date. For a fall crop, sow by Aug 23, or by Aug 10 to be safe. That's 54 days back from the first-frost date.

When to plant turnips in Grand Junction

Hardy crop. CSU says turnips can go in as early as 2–4 weeks before the average last frost, once the soil can be worked and is at least 40°F. In Grand Junction, that's roughly Mar 31 – Apr 14 going by the typical date, or Apr 16–30 going by the safer date. For fall, count back 64 days from the first-frost date. That means sowing by Aug 13, or by Jul 31 to be safe.

When to plant beets in Grand Junction

Semi-hardy crop. CSU allows planting beets as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Grand Junction, that's roughly Apr 14–28 by the typical date or Apr 30 – May 14 by the safer date. For fall, count back 74 days from the first-frost date. That means sowing by Aug 3, or by Jul 21 to be safe.

When to plant swiss chard in Grand Junction

Semi-hardy crop. CSU allows planting swiss chard as early as 0–2 weeks before the average last frost, in soil at 40°F or warmer. For Grand Junction, that's roughly Apr 14–28 by the typical date or Apr 30 – May 14 by the safer date. For a fall crop, sow by Aug 3, or by Jul 21 to be safe. That's 74 days back from the first-frost date.

When to plant parsnips in Grand Junction

Semi-hardy crop. Per CSU, parsnips can go in as early as 0–2 weeks before the average last frost: roughly Apr 14–28 in Grand Junction (typical date) or Apr 30 – May 14 (safer date). The soil should be at least 35°F.

When to plant sweet corn in Grand Junction

Tender crop. Sow sweet corn around the average last frost, per CSU: about Apr 28 in Grand Junction. Waiting until May 14 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 50°F.

When to plant cucumbers in Grand Junction

Tender crop. Sow cucumbers around the average last frost, per CSU: about Apr 28 in Grand Junction. Waiting until May 14 cuts the chance of a later 32°F night to 1 in 10. Seeds need soil of at least 60°F. For a fall crop, sow by Jul 25, or by Jul 12 to be safe. That's 83 days back from the first-frost date.

When to plant eggplant in Grand Junction

Very tender crop. Following CSU Extension's rule (2+ weeks after the average last frost), set eggplant out around May 12 with the typical date, May 17 for a balanced choice, or May 28 with the safer 10% date. Sow seeds indoors Mar 15 – Apr 5, 6–9 weeks before transplanting on May 17. Using CSU's typical 60 days from transplant to harvest, eggplant plants set out on May 17 would start producing around Jul 16. That's 92 days before the typical first frost (Oct 16).

When to plant cantaloupe in Grand Junction

Very tender crop. CSU Extension's rule is to plant cantaloupe at least 2 weeks after the average last frost. That's about May 12 using the typical date, May 17 as a balanced choice, or May 28 if you go by the safer 10% date. Seeds need soil of at least 60°F.

When to plant watermelon in Grand Junction

Very tender crop. CSU Extension's rule is to plant watermelon at least 2 weeks after the average last frost. That's about May 12 using the typical date, May 17 as a balanced choice, or May 28 if you go by the safer 10% date. Seeds need soil of at least 60°F.

When to plant winter squash in Grand Junction

Very tender crop. CSU Extension's rule is to plant winter squash at least 2 weeks after the average last frost. That's about May 12 using the typical date, May 17 as a balanced choice, or May 28 if you go by the safer 10% date. Seeds need soil of at least 60°F.

When to plant garlic in Grand Junction

CSU Extension's Colorado guidance is to plant garlic in early October, before October 15 (Oct 1–14). That's a fixed statewide window, not one computed from frost data. At Grand Junction Walker Field, the typical first hard freeze (28°F) is Oct 27, 13 days after the window ends.

How these dates are calculated

CSU states its spring rules relative to “the average last spring frost.” We use the 50% date as that average and also show the 30% and 10% anchors. See the methodology for details and limitations.

FAQ

When should I start seeds indoors in Grand Junction?

Start tomatoes Apr 13–27 and peppers Mar 22 – Apr 5. Both dates count back from a balanced (30%-risk) transplant date using CSU's transplant ages.

When should I plant tomatoes outside in Grand Junction?

About Jun 1, at every risk level. CSU wants tomatoes out 2+ weeks after the average last frost (that rule alone gives about May 12 here) and nights above 52°F. At Grand Junction Walker Field, the average nightly low first rises above 52°F on Jun 1, later than the frost-rule date, so the night rule sets the date.

What can I plant in Grand Junction in the fall?

Counting back from the typical first frost (Oct 16) with UNL Extension's method: peas by Jul 29; lettuce (leaf) by Aug 3; carrots by Jul 24; beans (snap) by Jul 20; summer squash by Jul 30; broccoli by Jul 29 (transplants); cabbage by Jul 9 (transplants); kohlrabi by Aug 13; green onions by Aug 3; radishes by Sep 2; spinach by Aug 23; turnips by Aug 13; beets by Aug 3; swiss chard by Aug 3; cucumbers by Jul 25. Garlic goes in Oct 1–14.

When should I plant garlic in Grand Junction?

In early October, before October 15 (Oct 1–14), per CSU Extension's Colorado guidance.

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